Why Did Lagrange Prove the Parallel Postulate?

When

Start: 09/19/2007 - 3:00pm End : 09/19/2007 - 5:00pm

Category

Colloquium

Speaker

Dr. Judith Grabiner (Pitzer College)

Abstract

In 1806, Joseph-Louis Lagrange (1736-1813) read a memoir proving Euclid's parallel postulate to the Institut de France in Paris, but stopped, as the story goes, saying "I have to think about this some more." We'll look at Lagrange's still unpublished Paris manuscript on this subject, and place this activity in the context of his mathematical career. We will look also at how the ideas in this manuscript are related to Lagrange's philosophy of mathematics, Newton's physics, and Leibniz's Principle of Sufficient Reason. Finally, we will reflect on what this episode tells us about eighteenth-century attitudes toward geometry, space, and the universe.